Process for rendering proteinaceous textile materials water repellent



Patented June 10, 1952 UNITED STATES PATENT OFFICE .PR'OCESSFOR RENDERING .PROTEINA- CEOUS TEXTILE MATERIALS -WATEB REPELLENT 'Arnold M. Sookne, Silver SpringpMi-yandAlfred E., Brown, Washingtongl); 0.; asslgnors to, Harris .Besearch Laboratories, a partnership No Drawing. ApplicatibnfJlily'ZB, 1948,, "Serial N0.*41,I8,3

This invention relates to a process;for,-render- .ingpmteinaceous -'textile materials water repel- :lent,andnmore-particularly toa.,-Drocess for1ren- V xderingnwoolrfabrics water repellent by the application thereto of very dilute solutions of soap :and 'ofialuminum salt.

'Antohjectyoftthe invention isto provide a process fonconferring "water ,repellency'on ,proteina- :ceous textiles suchu'as wool, silk, and synthetic zproteinlfabrics. A-further object is to provide a process-Which maybe used to restore water re- :pellencyio fabrics. the waterrepellentflnish of which hasbeen deteriorated by laundering or dry "cleaning; The process maybe reapplied to the rsameqfabric as .many times as may be desired, when: retreatmentisnecessary, with the production 'oftanexc'ellentfinish each time. The processcisyzalsc applicable .to wool .fa'brics which have been subjected to chlorination or other shrinkproofing-treatment Anotherobjectpfthe invention is. to provide 'anzcimprovred {process-for rendering. protelnaceous textile: materials :water rrepllent, which process is characterized. by extreme simplicity of operation and economy: ofwtime, labor and materials.

Atfurtheriobject is to;provide aprocess for producin'grwaterrepellent proteinaceous'fabrics havingunimpairedi hand or feel and exhibiting no undesirable harshness orboardiness; Fabrics treated in accordance with the process have excellent :spray ratings and dynamic absorption valueswwhenwtested. for these ,properties as described in Fed-Spec; CCC-T-llll-a.

Another object-of .theinvention is .to: provide. a processiforxrendering woolen felts water repellent without 'adverselyafiecting-their flexibility or handle.

Typically, the process of the invention includes applying to a proteinaceous textile :material, in

fabric, skein; yarn, felt, orother'convenient form, an: aqueous solution of a water-rsolublefatty acid soap in a concentration ofirom 001% to 1.0%

and thereafter applying to the material aavatersoluble aluminum salt in a concentration :offrom 0.05 %:to 120%.

Preferablythe 'proteinaceous textilematerial is first immersed in an aqueous :solution of a'fatty 'acid soap in a concentration of less than about 0.5%;aconcentration ofra'bout 0.25%"being characteristic, andis agitated therein fora period of from about m'inutes to about .15 minutes, the temperature of the bath being kept .atiabout .70

F; "to 140 The thus treated. material. is .then removed 'iromtheusoap bath and is rinsed in warm "water *to remove any "excess .soap. There- 50 1 our process.

4 Claims. (01. iii-e141) after, the rinsed, soap "treated material is aimmersed in a second bath comprising an aqueous solution of an aluminum salt in a concentration of from -about 0.05% to 1.0% and agitated-thermin for a period of from about'3 minutes tOTflbOut 5 minutes, the temperature of the bath being maintained at from 70F.to 140 Finally, the material is rinsed in warm water'and dried.

The soap treating bath may include'eitherihigh '10 l or low titer water-soluble fatty'acid soap, -or..-sa1ts of fatty acids such as sodium stearate,-'sodium oleate, sodium myristate, ammonium oleate,*potassium 'stearate, and the like, and mixtures thereof. The term fatty acid soap" is used in the claims in a broad sense and is intended to includethe foregoing and their equivalents. The soap solution should have a soap concentration of less than about 1.0%, the low range of concentrations of from 0.01%to 0.25% giving very 'goodresults. The preferredwelghtratio of'the bath to'the material beingtreated is about 20 to l. The bath temperature is kept at apointatwhich the soap is soluble, and at which danger of felting thematerial .beingr'treated is-minimized. In

2 "general, "temperatures of "from 70 to 110? .F.

are preferred. Agitation is desirable and the P riod of treatment may run from 5 to 15 minutes, although a longer period will do no harm. The time of treatment is not critical and will be dependentonthe ease of wetting of the particular material being treated.

The soap treated material, after rinsing, is found to .havepioked up .from about 0.2% to about 0.6% of soap by weight based-on the weight of thefabric.

The aluminum salt baths of the inventioninclude aqueous solutions of water-soluble alumi-- num salts such as thesulfate, acetate, nitrate, chloride, formateand othersimplesalts of aluminum. It may also include various alums such as ammonium alum, potash alum, sodium alum and the like. The term ,aluminum salt "as used herein is intended to include Without limitation the simple water-soluble aluminum salts and alums.

'.1satisractcrythrush somecases andwehavealso 35 found that solutions as concentrated as 1.0% may sometimes be used. However, baths containing more aluminum salt than about 1.0% produce inferior products.

Treatment in the aluminum salt bath may be carried out similarly to treatment in the soap bath. The weight of the bath is preferably about 20 times the weight of material treated. The bath is kept at a safe non-felting temperature of about 70 F. to 140 F. The time of treatment may be from about 3 minutes to about 5 minutes, although longer times may be employed. The time may be as little as one minute or as long as necessary to produce good penetration. The time of treatment is not critical and is dependent on the type of material being treated, as well as on the equipment used. For example, using padding equipment, short treating times are suitable, whereas immersion treatments require long periods of time.

Wool fabrics, when treated in accordance with the present-process, acquire an add-on of about 0.2% to 0.6% by weight of the dry fabric. The

added substance contains approximately 0.1% or less of aluminum on the basis of the dry fabric, the remainder being fatty acid. Thus, it is seen that a relatively low add-on treatment is provided with the production of excellent Water repellency.

Although we do not wish to be restricted to any theory, it is our belief that the protein molecule of the fabric binds both fatty acid and aluminum with the formation of a complex which is probably responsible for the water resistance obtained.

In order to further illustrate the method of the invention, the following examples are given:

Example I Wool fabric is agitated in 0.25% high titer soap solution for minutes at 100 F., after which it is rinsed, and agitated in a solution of 0.1% aluminum sulfate octadecahydrate for 5 min- 'utes at 100 F. (:1 bath is satisfactory). The

fabric is then rinsed and dried at 125 F. The fabric acquires an excellent Water repellent finish by this treatment.

Example I I A blended synthetic protein fabric cellulose acetate-50% protein fiber) is passed through 0.25% low titer soap solution, rinsed. and agitated in 0.1% aluminum sulfate octadecahydrate for 5 minutes, then rinsed and dried at 130 F. The fabric no longer puckers on exposure to drops of water.

Example III soap solution for 15 minutes at 100 F., rinsed once with water, and then treated in a solution of 0.1% aluminum acetate for 5 minutes at 100 F. A 20:1 bath to goods ratio is satisfactory for these operations. The fabric is then rinsed and 2,599,590 i'ij; f .i ".1

4 dried at F. An excellent water repellent finish is obtained by this treatment.

Example V oellent water repellent finish is obtained by this treatment.

' Example VI Wool felt is treated in a 0.3% solution of high titer soap at 110 F. for 10 minutes, passed through squeeze rolls, and then, without rinsing, treated in a 1% solution of aluminum sulfate at F. for 15 to 20 minutes. The felt is then passed through squeeze rolls and dried. A Water repellent felt of excellent hand is produced in this manner; I

The rendering of woolen felts water repellent by this treatment is particularly advantageous over conventional treatments. Wool felts are often used in low temperature areas, such as in the Arctic, for protective purposes. They are also used under low temperature conditions for industrial applications. At these temperatures the maintenance of flexibility is an important property. Felts treated by this process remain flexible in the dry state because of low add-on and lack of brittle finishes. They also remain flexible in the wet state because only small amounts of water, which subsequently freeze, are absorbed. On the other hand, felts treated'with conventional aluminum-wax finishes have higher add-ons, and these felts lose their flexibility, and become very stiff, either wet or dry, at low temperatures. On bending, such materials actually break apart. Felts treated by the process of the invention as herein described are advantageously employed in such low temperature applications.

Because of the low add-on nature of the treatment, the handle and air permeability of treated fabrics is not impaired. The use of larger amounts of aluminum salt clogs the pores of fabrics, and also results in a tacky handle. It has been found that this tacky handle is averted when the concentration of soap on the fabric is within the limits described herein.

Where particular hydrates of aluminum salts are referred to herein it will be understood that the equivalent weight of the anhydrous salt or other hydrate may be used instead. 7

While we prefer to employ our soap and aluminum salt baths in the ratio of about 20 parts by weight of each to 1 part by weight of the proteinaceous textile material, we may vary this ratio within the limits of about 10 parts to 30 or more parts by Weight of the bath to one part by weight of the textile material. Non-soap detergents may be added to the soap or the aluminum salt baths to obtain improved Wetting and penetration.

From the foregoing description it will be seen that the present invention provides a process for conferring water repellency to proteina'ceous textile materials such as wool, silk or synthetic protein textile fabrics and the like or mixtures including the same. Certain fabrics which wet rapidly and pucker do not exhibit such deficiencies after treatment by this process.

A wide variety of woolen fabrics of different construction such as serge, fiannels, meltons, tropical Worsteds, napped blankets, covert, and

tightly woven worsteds show greatly improved water resistance after treatment by the process. Woolen felts may also be rendered water repellent by this process. Treated felts acquire a soft handle as a result of the treatment.

The finish produced by the process of the invention is "semi-durable to laundering and dry cleaning. However, the treatment can be readily re-applied to fabrics if the finish has become deteriorated through wear and repeated launderings or dry cleanings.

We have found that it is not essential to rinse the material between the soap and aluminum salt treatments. The material may be merely squeezed or wrung after it has been soaped and then immediately subjected to the aluminum salt treatment; or it may be rinsed as many as two or three times between the soap and aluminum salt baths without detracting from the quality of the finish produced.

This application is a continuation-in-part of our co-pending application Serial No. 713,916, filed December 4, 1946, now abandoned, for Process for Rendering Proteinaceous Textile Materials Water Repellent.

We claim:

1. Process for rendering proteinaceous textile materials water repellent which comprises applying to the proteinaceous textile material an aqueous solution of a water-soluble fatty acid soap in a concentration of about 0.25% and thereafter applying to the material an aqueous solution of a water-soluble aluminum salt in a concentration of about 0.1%.

2. Process for rendering wool textile fabrics water repellent which comprises immersing the fabric in an aqueous solution of a water-soluble fatty acid soap in a concentration of about 0.25% and at a temperature of about 70 F. to 110 F., and agitating the fabric in said solution for a time sufficient to provide substantial penetration of the fabric by the solution; rinsing the fabric in warm water to remove excess soap; immersing the thus treated fabric in an aqueous solution of aluminum sulfate in a concentration of about 0.1% and at a temperature of about 0 F'. to F., and agitating the fabric in said second solution for a time sufiicient to provide substantial penetration of the fabric by the solution; the weight ratio of said solutions to said fabric being about 20 to 1; rinsing the fabric in warm water; and drying the fabric.

3. Process for rendering proteinaceous textile materials water repellent which comprises applying to the proteinaceous material an aqueous solution of a water-soluble fatty acid soap in a concentration of about 0.25%} and thereafter applying to the material an aqueous solution of aluminum sulfate in a concentration of about 0.1%

4. Process for rendering proteinaceous textile materials water repellent which comprises applying' to the proteinaceous material an aqueous solution of a water-soluble fatty acid soap in a concentration of about 0.25% and thereafter applying to the material an aqueous solution of aluminum acetate in a concentration of about 0.1%.

ARNOLD M. SOOKNE. ALFRED E. BROWN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number. Name Date Re.18,'718 Schlierer Jan. 24, 1933 80,640 Lowrey Aug. 4, 1868 742,212 Muller-Jacobs Oct. 27, 1903 1,500,026 Mendelsohn July 1, 1924 2,110,383 Nathansohn Mar. 8, 1938 FOREIGN PATENTS Number Country Date 403,957 Great Britain Dec. 27, 1933 

1. PROCESS FOR RENDERING PROTEINACEOUS TEXTILE MATERIALS WATER REPELLENT WHICH COMPRISES APPLYING TO THE PROTEINACEOUS TEXTILE MATERIAL AN AQUEOUS SOLUTION OF A WATER-SOLUBLE FATTY ACID SOAP IN A CONCENTRATION OF ABOUT 0.25% AND THEREAFTER APPLYING TO THE MATERIAL AN AQUEOUS SOLUTION OF A WATER-SOLUBLE ALUMINUM SALT IN A CONCENTRATION OF ABOUT 0.1%. 